The use of the likelihood ratio for evaluative and investigative purposes in comparative forensic handwriting examination

This paper extends previous research and discussion on the use of multivariate continuous data, which are about to become more prevalent in forensic science. As an illustrative example, attention is drawn here on the area of comparative handwriting examinations. Multivariate continuous data can be obtained in this field by analysing the contour shape of loop characters through Fourier analysis. This methodology, based on existing research in this area, allows one describe in detail the morphology of character contours throughout a set of variables. This paper uses data collected from female and male writers to conduct a comparative analysis of likelihood ratio based evidence assessment procedures in both, evaluative and investigative proceedings. While the use of likelihood ratios in the former situation is now rather well established (typically, in order to discriminate between propositions of authorship of a given individual versus another, unknown individual), focus on the investigative setting still remains rather beyond considerations in practice. This paper seeks to highlight that investigative settings, too, can represent an area of application for which the likelihood ratio can offer a logical support. As an example, the inference of gender of the writer of an incriminated handwritten text is forwarded, analysed and discussed in this paper. The more general viewpoint according to which likelihood ratio analyses can be helpful for investigative proceedings is supported here through various simulations. These offer a characterisation of the robustness of the proposed likelihood ratio methodology.     

Raman spectroscopy and microspectrophotometry of reactive dyes on cotton fibres: Analysis and detection limits

A collaborative study on Raman spectroscopy and microspectrophotometry (MSP) was carried out by members of the ENFSI (European Network of Forensic Science Institutes) European Fibres Group (EFG) on different dyed cotton fabrics. The detection limits of the two methods were tested on two cotton sets with a dye concentration ranging from 0.5 to 0.005% (w/w). This survey shows that it is possible to detect the presence of dye in fibres with concentrations below that detectable by the traditional methods of light microscopy and microspectrophotometry (MSP). The MSP detection limit for the dyes used in this study was found to be a concentration of 0.5% (w/w). At this concentration, the fibres appear colourless with light microscopy. Raman spectroscopy clearly shows a higher potential to detect concentrations of dyes as low as 0.05% for the yellow dye RY145 and 0.005% for the blue dye RB221. This detection limit was found to depend both on the chemical composition of the dye itself and on the analytical conditions, particularly the laser wavelength. Furthermore, analysis of binary mixtures of dyes showed that while the minor dye was detected at 1.5% (w/w) (30% of the total dye concentration) using microspectrophotometry, it was detected at a level as low as 0.05% (w/w) (10% of the total dye concentration) using Raman spectroscopy. This work also highlights the importance of a flexible Raman instrument equipped with several lasers at different wavelengths for the analysis of dyed fibres. The operator and the set up of the analytical conditions are also of prime importance in order to obtain high quality spectra. Changing the laser wavelength is important to detect different dyes in a mixture.     

Victims' influence on intimate partner violence revictimization: an empirical test of dynamic victim-related risk factors

Research has reported that not only characteristics of the perpetrator but also characteristics of the victim influence risk for intimate partner violence (IPV). This would suggest that prevention of repeat abuse could benefit from a focus on both perpetrator and victim characteristics. Knowledge on factors that are within victims' sphere of influence is important because a focus on victim characteristics can help victims to take control of their situations and can thereby empower them. Dynamic victim-related factors are most relevant here as these are factors that can be changed or improved, in contrast to unchangeable static factors. Surprisingly, however, little is known about how victim-related factors affect risk for revictimization of IPV. The current study was conducted among a Dutch sample of 156 female, help-seeking IPV victims. The aim was to examine to what extent prior IPV and, in particular, dynamic victim-related factors influence risk for future IPV. In accordance with the models articulated by Foa, Cascardi, Zoellner and Feeny, we studied how the three key factors from their models-partner violence, victims' psychological difficulties, and victims' resilience-related to risk for IPV revictimization. Results provide support for several key factors (partner violence and victims' psychological difficulties) and, moreover, show which victim-related factors contribute to revictimization risk above and beyond the influence of prior violence committed by a partner against the victim (i.e., victims' prior IPV victimizations). Findings are discussed in terms of recommendations for practice and future research.     

Determining the Refractive Index Variation within Panes of Vehicle Windshield Glass

Refractive indices of seven double‐paned vehicle windshields were measured to assess the variation across the pane of glass and to evaluate collection techniques for known glass standards by comparing false negative rates. Measurements were made using a Foster and Freeman GRIM3 instrument, and a minimum of 240 measurements were made per pane. The mean SD of the windshields was 0.00004. It was further determined that collecting a known sample from two different sections of a shattered windshield gave the lowest rate of false negatives when using ± 2 standard deviations to estimate the RI variation of the known glass. Additionally, refractive indices often were highest in the center of the windshield and decreased toward the left and right edges; in approximately half the sample set, the two panes of a single windshield were differentiated by one or more properties.     

Internal Validation of Human Mitochondrial DNA Quantification Using Real‐Time PCR

The quantity of mitochondrial DNA (mtDNA) template added for amplification and subsequent dye terminator reactions is critical for obtaining quality sequence data. Validation of a human mtDNA real‐time quantitative PCR (qPCR) assay demonstrated its high degree of reproducibility and precision as well as an extremely sensitive threshold of detection (0.0001 pg/μL or approximately six human mtDNA copies/μL). A study of 35 nonprobative bone and teeth evidence samples revealed that 20 pg of mtDNA template is recommended for successful HV1 and HV2 sequence analysis; however, as little as 0.013 pg can generate a full mtDNA profile when using enhanced amplification reactions. The assay can also detect PCR inhibition and is useful for identifying samples that may benefit from re‐purification. Overall, the assay is an excellent method to quantify mtDNA and is useful for determining the best analytical approach for successful sequencing.     

Driving Under the Influence of Synthetic Cannabinoid Receptor Agonist XLR‐11

The case of a 22‐year‐old male Caucasian driver is presented. He was involved in a traffic collision. At the roadside, he displayed blank stare and mellow speech with a barely audible voice. A DRE found low body temperature, rigid muscle tone, normal pulse, lack of horizontal and vertical gaze nystagmus, nonconvergence of the eyes, dilated pupil size, and normal Pupillary reaction to light. A standard toxicology DUID protocol was performed on the driver's whole blood including ELISA and GC‐MS drug screens with negative results. Additional drug screening was undertaken for bath salts and synthetic cannabinoid receptor agonists by LC‐MS/MS by a commercial laboratory and identified the synthetic cannabinoid receptor agonist XLR‐11 in the driver's blood. XLR‐11 was subsequently quantified at 1.34 ng/mL. This is the first documented case involving a driver operating a motor vehicle under the influence of the synthetic cannabinoid receptor agonist XLR‐11.     

The Influence of Congressional Preferences on Legislative Overrides of Supreme Court Decisions

Studies of Court–Congress relations assume that Congress overrides Court decisions based on legislative preferences, but no empirical evidence supports this claim. Our first goal is to show that Congress is more likely to pass override legislation the further ideologically removed a decision is from pivotal legislative actors. Second, we seek to determine whether Congress rationally anticipates Court rejection of override legislation, avoiding legislation when the current Court is likely to strike it down. Third, most studies argue that Congress only overrides statutory decisions. We contend that Congress has an incentive to override all Court decisions with which it disagrees, regardless of their legal basis. Using data on congressional overrides of Supreme Court decisions between 1946 and 1990, we show that Congress overrides Court decisions with which it ideologically disagrees, is not less likely to override when it anticipates that the Court will reject override legislation, and acts on preferences regardless of the legal basis of a decision. We therefore empirically substantiate a core part of separation‐of‐powers models of Court–Congress relations, as well as speak to the relative power of Congress and the Court on the ultimate content of policy.     

Mad Men in Bib Overalls: Media’s Horrification and Pornification of Rural Culture

The media play a key role in stereotyping as “ignorant and uncouth hillbillies” people who live in rural US communities. As well, since the early 1970s, popular films frequently portray rural areas as dangerous locations, places where urban people are at high risk of being savagely killed and tortured by demented, in-bred locals without conscience or constraint. Further, with the advent of the Internet, rural women continue to be depicted in a degrading, highly sexualized manner and “gonzo” pornographic videos of them are widely and freely accessible. Informed by feminist and cultural criminological modes of inquiry, this paper presents some exploratory research on rural horror films and pornographic videos. A key argument is that with the help of new information technologies, these media are normalized, mainstreamed, and contribute to the horrification/pornification of rural culture, and by doing so, mask the real issues about crime, violence, and gender relations in the rural context.     

Examining the prevalence and correlates of a ‘senior citizen discount’ in US federal courts

Few studies focus on age as a factor influencing judicial decision-making, in spite of the widespread use of age as a control variable. Although the limited research to have done so is inconsistent, most scholars agree that age may be race- and/or gender-graded in a manner that produces more severe sentences for certain race–gender–age combinations, especially for young males who are Black or Latino. Less consensus exists with regard to whether older defendants are granted more leniency in the sentencing process and, if so, if the effects of older age are also race- and/or gender-graded. The present study examines this question by examining data from the United States Sentencing Commission. The data presented reveal three noteworthy findings. First, a ‘senior citizen discount’ exists insofar as judges afford more leniency in sentencing to older offenders than their younger counterparts. Second, compared to older males, older females were treated with greater leniency by judges. Finally, whereas Latinos 60 and over were treated with greater severity at the stage of incarceration compared to similarly situated Whites, Blacks received shorter sentence lengths on average. These results are analyzed within the framework of the focal concerns perspective.